Hole perforation plate for manufacturing of a toothbrush head and part thereof

ABSTRACT

A method for manufacturing a toothbrush head or a part thereof comprises steps of providing a plurality of bristle tufts; providing a hole perforation plate comprising a front surface, a back surface, a thickness therebetween, and a plurality of holes grouped into a plurality of hole arrangements, wherein the front surface is uneven in an area of the hole arrangement; pushing the bristle tufts through the holes; and fusing ends of the bristle tufts at the back surface of the plate by application of thermal energy, thereby forming a plurality of fuse balls that are larger than the holes of the plate; and mounting the plate with the plurality of bristle tufts into a brush head.

FIELD OF THE INVENTION

Modern brush heads, in particular toothbrush heads, show high designflexibility. Several requirements, such as deep cleaning, sensitivecleaning, gum massage, cleaning of tooth with dental brace etc. requiredifferent brush heads comprising various arrangements of different typesof cleaning elements. In addition, the consumer asks for a good mouthfeeling also during brushing which limits e.g. size or thickness of thetoothbrush head. Thus, an improved manufacturing process is needed thatallows high design flexibility in order to meet all requirements ofmodern toothbrushes. For example, different cleaning elements, such aselastomeric cleaning elements and different types of bristle tufts hasto be arranged together at one brush head securely. The presentinvention is directed to a hole perforation plate which can be used inmanufacturing of (tooth)brush heads, or parts thereof which show a highvariability of different types of cleaning elements.

BACKGROUND OF THE INVENTION

Methods of producing brush heads or parts thereof are already known inthe prior art. Fusing of the bristle tuft ends to form fuse balls is oneimportant step in most of the methods. The resulting fuse balls do notonly connect the individual bristle filaments of one bristle tuft witheach other, but also helps to securely mount the bristle tufts in thebrush head. In particular, fuse balls that are larger than the bristletufts may anchor the bristle tufts in brush heads.

One method of production using said anchoring is the anchor-free tufting(AFT) method developed by Bart G. Boucherie. Thereby the bristle tuftsare pushed through the holes of a hole perforation plate and the end ofthe tuft which is not intended for cleaning will be fused by applicationof thermal energy. The fuse balls formed thereby are larger than theholes so that the bristle tufts stuck at the backside of the holeperforation plate. The fuse balls may be combined with the holeperforation plate as well, e.g. by the thermal energy applied or byultrasound welding; then the perforation plate is mounted together withthe bristle tufts into a brush head (EP1142505B1). Homogenous size, formand shape of the fuse balls is not important for the AFT method.

In contrast, in the hot tufting method as developed by Ulrich Zahoranskythe bristle tufts are arranged in holes of a mold bar so that the fuseballs are available for over-molding with plastic material. During saidover-molding the brush head is formed at least partially and the bristletufts and the forming brush head are combined. Due to fuse balls thatare larger than the bristle tufts themselves undercuts are formed duringthe over-molding process so that the bristle tufts and the brush headare combined securely. Geometric requirements of the brush heads to beformed can be met using the hot tufting method.

There exists a continuous need in toothbrush manufacturing to furtherincrease flexibility in brush head design. Thereby, different types ofcleaning elements as well as different types of bristle tufts have to beincluded into one brush head securely. Thereby complex forms of plasticobjects are formed which require complex mold cavities. The more complexthe plastic object the more mold parts are usually needed. Inconsequence molding devices become larger in order to meet the geometricrequirements of the complex molds. Thus, it is an object of the moldingdevice described herein to produce complex plastic objects with minimalmold parts and small geometric dimensions.

SUMMARY OF THE INVENTION

According to one aspect there is provided a hole perforation platecomprising a front surface, a back surface, a thickness and one or moreholes, wherein the one or more holes are grouped into more than onearrangement of holes, wherein the more than one arrangement of holes canbe identical or different compared to each other regarding the number ofthe holes, the shape of the holes, the size of the holes, the distancebetween the holes, the arrangement of the holes, and a combinationthereof, and wherein the front surface is uneven in the area of thearrangement of the holes.

According to another aspect a method for producing a brush head, inparticular a toothbrush head or a part thereof is provided comprisingusing the hole perforation plate as disclose herein. In addition, thehole perforation plate may be used to provide bristle tufts for at leasttwo different method steps, preferably at least for fusing andover-molding.

According to another aspect a (tooth)brush head, or a part thereof isprovided that is manufactured using a method and/or a hole perforationplate as disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a side view of an example embodiment of a cleaning elementcarrier having a central protrusion;

FIG. 1B shows a cross-sectional view of an example embodiment of acleaning element carrier having a central protrusion and a centraldepression;

FIG. 1C shows a side view of an example embodiment of a cleaning elementcarrier having a central protrusion comprising bristle tufts;

FIG. 1D shows a cross-sectional view of an example embodiment of acleaning element carrier having a central protrusion and a centraldepression comprising bristle tufts arranged on a bristle field;

FIG. 2A shows a cross-sectional view of an example embodiment of acleaning element carrier comprising voids;

FIG. 2B shows a cross-sectional view of the example embodiment of thecleaning element shown in FIG. 2A, wherein the voids are filled withelastomeric cleaning elements;

FIG. 2C shows a cross-sectional view of an example embodiment of acleaning element carrier comprising a drive part at the back surface;

FIG. 2D shows a cross-sectional view of the example embodiment of acleaning element shown in FIG. 2C, wherein the drive part is securelyconnected to the carrier by a cover;

FIG. 2E shows a cross-sectional view of an example embodiment of acleaning element carrier comprising a drive part, elastomeric cleaningelements, and bristle tufts;

FIG. 3A shows a cross-sectional view of a hole perforation platecomprising a plurality of holes distributed in the hole perforationplate;

FIG. 3B shows a cross-sectional view of the hole perforation plate shownon FIG. 3 a , wherein bristle tufts are placed in the plurality ofholes;

FIG. 3C shows the hole perforation plate, shown in FIGS. 3A and 3B,rotated by 90 degrees, and an energy source for fusing the bristletufts' ends;

FIG. 3D shows the hole perforation plate, shown in FIGS. 3A-3C, whereinthermal energy is applied the melt the tufts' ends and form fuse ballsthereof;

FIG. 3E shows the hole perforation plate, shown in FIGS. 3A-3D after thefuse balls have been formed;

FIG. 3F shows the hole perforation plate, shown in FIGS. 3A-3E, whereinmolten material is filled into the mold and the fuse balls are embeddedinto the material of the cleaning element carrier;

FIG. 3G shows a cross-sectional view of another embodiment of a holeperforation plate, wherein a drive part is partially placed in a mold sothat molten material surrounds the fuse balls and a portion of the drivepart;

FIG. 3H shows the hole perforation plate shown in FIG. 3G, wherein thedrive part is integrated onto the cleaning element carrier;

FIG. 3I shows an embodiment of a hole perforation plate comprising acentral depression;

FIG. 4A shows a schematic cross-sectional view of a manual toothbrush;

FIG. 4B shows a schematic cross-sectional view of a toothbrush having areplacement brush head; and

FIG. 5 shows a top view of a hole perforation plate comprising threemolds for formation of a cleaning element carrier.

DETAILED DESCRIPTION OF THE INVENTION

The following is a description of numerous embodiments of a method ofproducing a brush head or a part thereof as well as the brush head orthe part thereof that are produced with the method as disclosed herein.The description is to be construed as exemplary only and does notdescribe every possible embodiment since describing every possibleembodiment would be impractical, if not impossible, and it will beunderstood that any feature, characteristic, structure, component, stepor methodology described herein can be deleted, combined with orsubstituted for, in whole or in part, any other feature, characteristic,structure, component, product step or methodology described herein. Inaddition, single features or (sub)combinations of features may haveinventive character irrespective of the feature combination provided bythe claims, the respective part of the specification or the drawings.

By “cm” as used herein is meant centimeter. By “mm” as used herein ismeant millimeter. By “μm” or “microns” as used herein is meantmicrometer. By “mil” as used herein is meant a thousandth of an inch.

As used herein, the word “about” means +/−10 percent.

As used herein, the word “comprise,” and its variants, are intended tobe non-limiting, such that recitation of items in a list is not to theexclusion of other like items that may also be useful in the materials,devices, and methods of this invention. This term encompasses the terms“consisting of” and “consisting essentially of”.

As used herein, the word “include,” and its variants, are intended to benon-limiting, such that recitation of items in a list is not to theexclusion of other like items that may also be useful in the materials,devices, and methods of this invention.

As used herein, the words “preferred”, “preferably” and variants, suchas “in particular” and “particularly” refer to embodiments of theinvention that afford certain benefits, under certain circumstances.However, other embodiments may also be preferred, under the same orother circumstances. Furthermore, the recitation of one or morepreferred embodiments does not imply that other embodiments are notuseful, and is not intended to exclude other embodiments from the scopeof the invention.

There is provided a method for producing a brush head, in particular atoothbrush head or a part thereof comprising providing at least twobristle tufts comprising a plurality of bristle filaments, wherein theat least two bristle tufts differ in at least one property. The term“bristle tuft” as used herein shall be understood as any shape, form,size and/or arrangement of bristle filaments of a predefined length. Anygeometric shape, form or arrangement that can be produced by groupingindividual bristle filaments can form a bristle tuft. Standard shapesthat are given as an example are round bristle tufts, elliptic bristletufts, sickle-shaped bristle tufts, bristle tuft stripes, orcombinations thereof. In addition, two or more bristle tuft may bearranged in a tuft-in-tuft arrangement, wherein the shape of eachindividual tuft may be the same or different and is combined from thealternatives given before. For example a round tuft may be arranged in around tuft, or a round tuft may be arranged in an elliptic tuft, or astriped tuft may be arranged in a round tuft etc. In a tuft-in-tuftarrangement the two tufts may differ in the at least one property or maybe identical regarding the at least one property. The at least twobristle tufts that differ in at least one property are arranged in ahole perforation plate comprising a front surface, a back surface, athickness and one or more, preferably a plurality of holes, wherein theone or more, preferably the plurality of holes is distributed in thehole perforation plate according to the desired bristle field of thebrush head or the part thereof to be produced.

In the following the hole perforation plate will be disclosed in moredetail. In one embodiment, the hole perforation plate comprises a frontsurface, a back surface, a thickness and one or more, preferably aplurality of holes, wherein the holes may be grouped into more than onearrangements of holes, wherein the more than one arrangements of holesmay be identical or different compared to each other, preferablyidentical of different regarding the number of the holes, the shape ofthe holes, the size of the holes, the distance between the holes and acombination thereof. That means the hole perforation plate may comprisea plurality of arrangements of holes, wherein each arrangementcorresponds to the desired bristle field of the brush head or the partthereof to be produced, preferably of round or an elongated form, morepreferred a form of a head of a manual toothbrush or a head for areplacement brush head of an electric toothbrush. Alternatively, thehole perforation plate may comprise only one arrangement of holes thatcorrespond to the desired bristle field. Preferably, the holeperforation plate comprises identical arrangements of holes, morepreferred the hole perforation plate comprises 4 identical arrangementsof holes. In addition, more than one hole perforation plates, e.g. twohole perforation plates, may be combined to a larger hole perforationplate. The number of holes in one arrangement may be in the range of 1to 60 holes, preferably 10 to 60 holes, more preferred 15 to 40 holes,more preferred 15 to 35 holes, more preferred 15 to 30 holes. Thedistance between neighboring holes in one arrangement is in the range of0.2 mm to 2.0 mm, preferably in the range of 0.4 mm to 1.8 mm, morepreferred in the range of 0.5 mm to 1.2 mm. The distance betweenneighboring arrangements in one hole perforation plate is defined bydesign and the molding process used, which might be at least 2 mm, inparticular in the range of 2 mm to 40 mm.

The shape of the holes in the hole perforation plate corresponds to theshape of the bristle tuft which shall be located in the correspondinghole. A bristle tuft can be manufactured in any form, wherein the formmay be adapted according to the function of the tuft, the position ofthe tuft within the bristle field, the form of the cleaning elementcarrier and/or a combination thereof. During location of the bristletuft in the holes of the hole perforation plate the bristle tuft adaptsthe shape of the hole and can be fixed in this shape during furtherprocessing steps, such as fusing. Suitable shapes of the holes of thehole perforation plate are round, half-round, sickle-shaped, elliptic,elongate, angled, e.g. quadrangular, trapezoidal, pentagonal, hexagonal,heptagonal, octagonal or a mixture thereof. All different shapes can becombined to each other, e.g. a half-round shape can be combined with aquadrangular shape or a trapezoidal shape might be combined with asickle-shape. Preferred holes of the hole perforation plate are round,oval, half-round, sickle-shaped, elongate or angled, more preferredround or oval.

In addition or alternatively, the size of a hole depends on the tuft tobe integrated. Thus, the size of a hole may be in the range of about 0.6mm² to about 40 mm². A suitable size of a hole for a round standardbristle tuft is in the range of 0.6 mm² to 3 mm², preferably in therange of 1.0 mm² to 2 mm², more preferred about 1.5 mm². In addition oralternatively, the hole perforation plate may also comprise hole(s) forbristle tufts having the size of a plurality of a standard bristle tuft,in particular the size of 2 to 25 bristle tufts, more particular 2 to 15bristle tufts, more particular 5 to 10 bristle tufts. A preferredembodiment of a large tuft comprising the size of more than one standardtuft may be for example a block bristle tufts comprising a combinationfrom about 5 to 15 bristle tufts. Accordingly, a preferred range forholes for block tufts might be in the range of about 8 mm² to about 24mm², more preferred in the range of about 8 mm² to about 16 mm².

The hole perforation plate to be used in the method as disclosed hereinmay be made from any suitable material which is resistant to the methodsteps as disclosed herein and which can be formed. A heat resistantmaterial is preferred, because the hole perforation plate as disclosedherein is used inter alia as part of a mold. A suitable material for ahole perforation plate as used herein are any heat resistant material,in particular metal and metal alloys, such as steel, in particularstainless steel, a heat resistant plastic, in particularpolytetrafluorethylene (PTFE) or polyetheretherketone (PEEK), ceramic ora combination thereof. The hole perforation plate may be produced by anymethod that allows to form high precision components, such as metalcasting, in particular aluminum casting, 3D-printing, vitrification,pulsed electrochemical machining (PECM), molding. Depending on themanufacturing method used the hole perforation plate may be a singlecomponent or a base component comprising several component parts. Forexample, the base component may be made from steel comprising cavitiesfor inserts comprising the hole arrangements as described above. Such anarrangement allows to use one base component for the manufacturing ofdifferent bristle fields just by changing the arrangements of holes. Inaddition, the arrangements of holes which need to be of high quality andhigh precision can be produced independently from the base component.

In a preferred embodiment, the hole perforation plate may comprise anuneven front surface, preferably an uneven front surface in the area ofthe arrangement of the holes, more preferred, wherein the front surfacein the area of the arrangement of the holes is a convex surface. Thus,the holes of one arrangement may be le located at different levels ofthe hole perforation plate. For example, the front surface may comprisea protrusion in the area of at least one arrangement of the holes, orthe front surface may comprise one or more protrusion(s) in the area ofeach arrangement of the holes. In a preferred embodiment the one or moreprotrusion(s) in the front surface of the hole perforation plate isa/are central protrusion(s). Said central protrusion(s) may comprise thearea of at least one hole and at most the area of all holes of the holeperforation plate which belong to one bristle tuft arrangement. Inaddition or alternatively, the one or more protrusion(s), in particularcentral protrusion(s) may cover at least 10% of the area of the frontsurface, preferably at least 15% of the area of the front surface, morepreferred at least 20% of the front surface. The central protrusion mayprotrudes from about 0.2 mm to about 0.6 mm from the front surface,preferably from about 0.3 to about 0.5 mm from the front surface, morepreferably from about 0.35 mm to about 0.45 mm from the front surfaceand even more preferred the central protrusion protrudes about 0.4 mmfrom the front surface.

According to the method as disclosed herein the hole perforation plateas disclosed herein comprises through-holes for bristle tuft generation,i.e. the holes are as long as the plate is thick and the bristle tuftscan be relocated within the holes and with different distances to thefront surface of the hole perforation plate. In addition, the holeperforation plate may also comprise blind holes, wherein the blind holesmay be used for elastomeric cleaning elements.

A suitable thickness of the hole perforation plate may be in the rangeof 5 mm to 20 mm, preferably 6 mm to 14 mm. In addition, the holeperforation plate may comprise more than one layers, in particularwherein the more than one layer may consist of different materials. Asuitable material for the first layer comprising the front surface isheat resistant and allows to form high precision holes, such asstainless steel. A suitable material for a second layer may be less heatresistant, such as plastic material. In addition, the hole perforationplate can also be combined with a stopper plate. Therefore, the backsurface of the hole perforation plate is combinable with such a stopperplate, wherein the stopper plate may comprise a flat surface or maycomprise protrusions corresponding in form and shape to the arrangementsof holes. The stopper plate may be used for example, to arrange thebristle tufts orthogonally in the holes, in particular to change and/orrelocate the position of the bristle tufts in the holes of the holeperforation plate during different process steps.

The at least one property of the at least two bristle tufts which isdifferent according to the method as disclosed herein is selected fromthe size of the bristle tuft, the form of the bristle tuft, the positionof the bristle tuft in the hole perforation plate and/or in the desiredbristle field of the brush head to be produced, the material of thebristle filaments, the color of the bristle filaments, the diameterand/or cross-section of the bristle filaments, the shape of the bristlefilaments, additives present in the bristle filaments or a combinationthereof.

The term “bristle field” as used herein shall mean the arrangement ofmore than one, preferably a plurality of bristle tufts. Thereby, theterm is used irrespectively from the location of the arrangement, e.g. abristle field might be arranged in the hole perforation plate, in a moldbar, in a part of a brush head, in a brush head or in a toothbrush.

Bristle filaments may be for example monofilaments made from plasticmaterial. Suitable plastic materials used for bristle filaments may bepolyamide (PA), in particular nylon, polyamide 6.6, polyamide 6.10 orpolyamide 6.12, polybutylene terephthalate (PBT), polyethyleneterephthalate (PET) or mixtures thereof.

The circumference of the bristle filaments may be substantially round orthe circumference may comprise one or more recesses, such as X-tapebristle filaments or may alter along the length axis of the bristlefilament. The diameter of a round bristle filament may be in the rangefrom about 4 mil (0.1016 mm) to about 9 mil (0.2286 mm), in particularin the range of about 4 mil (0.1016 mm) to about 7 mil (0.1778 mm), moreparticular in the range of about 5 mil (0.127 mm) to about 6 mil (0.1524mm) or any other numerical range which is narrower and which fallswithin such broader numerical range, as if such narrower numericalranges were all expressly written herein.

In addition, to the standard bristle filaments having the diameters asgiven above super-thin bristle filaments are used in toothbrushes.Super-thin bristle filaments have a smaller diameter compared tostandard bristle filaments and may act like floss during normalbrushing. The diameter of super-thin bristle filaments may be in therange from about 2 mil (0.0508 mm) to about 4 mil (0.1016 mm) or anyother numerical range which is narrower and which falls within suchbroader numerical range, as if such narrower numerical ranges were allexpressly written herein. Bristle filament diameters are produced with atolerance of 10%.

In addition to bristle filaments with a substantially constant diameteralso bristle filaments may be used which diameter decreases towards theends. These kind of tapered bristle filaments are based on standarddiameter bristle filaments which ends are chemically tapered. Suitabletapered bristle filaments are provided for example by BBC, Korea.

In addition, bristle filaments may be used which comprise an irregulardiameter, i.e. which comprise at least one recess. A “recess” asunderstood herein in the bristle filament circumference, diameter,cross-section and/or volume shall mean any depression, cavity, slot orother geometric recess which amends the bristle filament volume. Thebristle filament comprising at least one recess in its circumference maycomprise one or more recesses along the circumference of the bristlefilament. A suitable example for a bristle filament comprising at leastone recess is an X-shaped bristle filament. X-shaped bristle filamentscomprise four recesses and two lines of reflection symmetry eachcrossing two recesses which are located opposite to each other. Inaddition, all four recesses might be equal. The included angle of theX-shape bristle filaments might be in the range of from about 40° toabout 160°.

Length of the bristle filaments depends on the intended use. Generally,a bristle filament can be of any suitable length for transporting, suchas about 1300 mm and is then cut into pieces of the desired length. Thelength of a bristle filament in a toothbrush influences the bendingforces needed to bend the bristle filament. Thus, the length of abristle filament can be used to realize different stiffness of bristlefilaments in a bristle field of a brush head. The typical length of abristle filament for a brush, in particular a toothbrush, may be in therange from about 5 mm to about 20 mm, in particular in the range fromabout 6 mm to about 15 mm, more particular in the range of about 7 mm toabout 12 mm or any other numerical range which is narrower and whichfalls within such broader numerical range, as if such narrower numericalranges were all expressly written herein.

In addition, the bristle filament material may comprise additives suchas abrasives, color pigments, flavors etc. in order to provide anindicator filament. An “indicator filament” as understood herein is anyelement which is amended over time and/or use thereby indicating thestatus of the toothbrush. For example, an indicator element may changeor wear off its color over time and/or use. The coloring on the outsideof the material is slowly worn away during use to indicate the extent towhich the bristle filament is worn. Suitable additives to bristlefilaments used for bristle tufts are for example UV-brighteners,signaling substances, such as the indicator color pigments and/orabrasives. For example, an abrasive such as kaolin clay may be addedand/or the bristle filaments may be colored at the outer surface.

Several bristle filaments are grouped to form one bristle tuft. The term“bristle tuft” as used herein shall be understood as any shape, form,size and/or arrangement of bristle filaments of a predefined length. Anygeometric shape, form or arrangement that can be produced by groupingindividual bristle filaments can form a bristle tuft. Standard shapesthat are given as an example are round bristle tufts, elliptic bristletufts, sickle-shaped bristle tufts, bristle tuft stripes, orcombinations thereof. A suitable number of filaments to form one bristletuft may be for example in the range of about 10 to about 80 filaments,or in the range of about 15 to about 60 filaments, or in the range ofabout 20 to about 50 filaments, or any other numerical range which isnarrower and which falls within such broader numerical range, as if suchnarrower numerical ranges were all expressly written herein.

After arranging the at least two bristle tufts in the hole perforationplate an energy source, in particular a thermal energy source isarranged in a predefined distance to the front surface of the holeperforation plate so that the ends of the at least two bristle tufts andthe energy source are arranged contactless. In addition, the at leasttwo bristle tufts are arranged in a fusing position, wherein the ends ofthe at least two bristle tufts which shall be fused are arranged in thehole perforation plate at different distances to the front surfaceresulting in different distances of the bristle tuft ends to the energysource, wherein the distance is adjusted according to the at least oneproperty of the at least two bristle tufts. Due to said differentdistances the ends of the bristle tufts will melt equally although theyprovide at least one different property. The term “melt equally” as usedherein shall mean that the fusing process of at least two differentbristle tufts is standardized so that fuse balls of a similar form andshape are formed in the same fusing time.

After arranging the at least two bristle tufts in fusing positionenergy, in particular thermal energy is supplied from the energy sourceto the ends of the at least two bristle tufts until fuse balls areformed at the end of the at least two bristle tufts.

The bristle filaments of one bristle tuft are connected to each other atone end and form a fuse ball. The term “fuse ball” as used herein shallbe understood as the molten filament material connecting the bristlefilaments of one bristle tuft after the fusing process. A fuse ball canbe of any shape or form including, but not limited to a plane, a planewith a depression, a plane with a concave surface, a plane with a convexsurface, a mushroom head, a dome shaped head or a combination thereof.The size of a fuse ball is based on the requirements to be met. The twomain requirements are to ensure that the tuft is securely connected intothe brush head (tuft retention) and to combine the individual filamentssecurely to each other (filament retention) according to governmentalregulations.

The formation of the fuse balls during the fusing process will be nowdescribed in more detail. The term “fusing process” as used herein shallbe understood as the whole process of applying energy, in particularthermal energy from an energy source to the end of at least one bristletuft in order to form a fuse ball at said bristle tuft end. Anon-limiting example fusing process starts with applying energy to theend to be fused of said at least one bristle tuft. Thereby, the ends ofthe bristle filaments soften, whereby bristle filament ends of bristlefilaments located at the outline of the bristle tuft soften faster thanbristle filament ends of bristle filaments located in the middle of thebristle tuft. Without being limited by theory it is believed that thebristle filaments located in the middle of a bristle tuft are shieldedagainst the energy applied by the energy source by the bristle filamentslocated at the outside of the bristle tuft. After softening bristlefilament material melts and starts to flow along the bristle filament.Thereby the free spaces between the bristle filaments of one bristletuft are filled with molten material. In addition, molten material flowsdown at the outline of the bristle tuft and the outline of the bristletuft at the bristle tuft end increases so that a projection is formed bythe fuse ball at the bristle tuft end. At this phase, the form of thefuse ball can be described as a plane with a central depression or aconcave plane. If further thermal energy is applied more bristle tuftmaterial melts and is combined with the fuse ball that has already beenformed. Thereby, the form of the fuse ball changes and the moltenmaterial accumulates at the bristle tuft end forming a convex shapedplane. If further thermal energy is applied the material that flows downat the outline before will be also accumulated at the top of the bristletuft end and a mushroom head or dome-shaped fuse ball will be finallybuilt. The fusing process can be interrupted at any time, in particularat the time when the form and shape of the fuse ball meets therequirements of further use of the bristle tuft. The fusing process asdescribed herein can be performed in horizontal or vertical arrangementof the hole perforation plate including the bristle tufts. Verticalarrangement might be preferred because vapors or steam which might beproduced during the fusing process are able to move away and do notaccumulate at the surface of the energy source. In addition, the energysource does not deform during fusing process.

According to the present disclosure it is preferred to fuse at leastuntil the bristle tuft ends are molten sufficiently. The term “meltsufficiently” as used herein shall be understood as applying energy,preferably thermal energy to the bristle filament ends until thematerial of the bristle filaments softens and melts and the moltenmaterial forms any kind of fuse ball as defined above.

A preferred form of a fuse ball according to the present invention is aplane, a plane with a depression, in particular a plane with a centraldepression, a concave plane, a slightly convex plane, a convex plane ora combination thereof. Preferably the fuse ball has the form of a plane.Thereby the geometric outline of the plane is defined by the geometricoutline of the bristle tuft which is defined and fixed by the geometricshape and form of the hole in the hole perforation plate. For example,round bristle tufts will form disc shaped planes, elliptic bristle tuftswill form elliptic planes, sickle-shaped bristle tufts will formsickle-shaped planes and bristle tuft stripes will form planes in formof a stripe.

In addition, the preferred outline of the plane is larger than theoutline of the bristle tuft so that the fuse ball forms a projection atthe bristle tuft end. In particular, the ratio of the outline of thefuse ball of the bristle tuft to the outline of the bristle tuft is atleast 1.05:1, preferably at least 1.1:1, more preferred at least 1.2:1,more preferred at least 1.3:1. In subsequent processes, such as moldingof the brush head or a part thereof, said projection will form anundercut so that the bristle tuft is connected with the brush head orthe part thereof securely.

The end of the bristle tuft that is opposite to the fuse ball representsthe end to be intended to clean the teeth. The ends of the bristles thatare intended to clean may be cut into a special profile, may be tapered,may be end-rounded and may be polished in order to provide a safe andcomfortable bristle tuft, which does not hurt the soft tissue in themouth.

According to the method as disclosed herein the distance between theenergy source, in particular thermal energy source and the bristle tuftsends to be fused is adjusted according to the properties of the bristletuft, such as the size of the bristle tuft, the form of the bristletuft, the position of the bristle tuft in the hole perforation plateand/or in the desired bristle field of the brush head to be produced,the material of the bristle filaments, the cross-section and/or diameterof the bristle filaments, the shape of the bristle filaments, the colorof the bristle filaments, additives present in the bristle filaments, ora combination thereof. All these properties influence the energy uptake,in particular the thermal energy uptake of the bristle tuft and thusinfluence the fusing process of each bristle tuft. Thus, the bristletuft ends are arranged with different distances to the energy source inorder to standardize the fusing process again.

A suitable distance from the energy source, e.g. the thermal energysource to the front surface of the hole perforation plate is in therange of from 0.5 mm to 1 mm, preferably in the range of from 0.5 mm to4 mm. The bristle tufts protrude from the hole perforation plate and themore the bristle tuft protrudes from the hole perforation plate thesmaller is the distance between the bristle tuft end to be fused and theenergy source.

As disclosed herein the properties influence the melting of the bristletufts and the formation of fuse balls. For example, the position of thebristle tuft in the hole perforation plate and/or in the desired bristlefield of the brush head to be produced influences the fusing process.Without being bound by a theory it is believed that bristle tufts whichare arranged at the periphery of a bristle field shield bristle tuftswhich are arranged in the middle of a bristle field. The more bristletufts are arranged around a subject bristle tuft the more thermal energyis shielded. Thus, if all bristle tufts of a bristle field shall befused in the same time and the fuse balls shall be similar, preferablysubstantially identically formed, the shielding effect can be equalizedby reducing the distance between the bristle tuft ends and the energysource. For example, when a plurality of bristle tufts is arranged inthe hole perforation plate in the fusing position the distance betweenthe energy source and the bristle tuft ends of bristle tufts that arearranged in the middle of the plurality of bristle tufts is shorter thanthe distance between the energy source and the bristle tuft ends ofbristle tufts that are arranged in the periphery of the plurality ofbristle tufts, preferably the distance between the energy source and thebristle tuft end of the bristle tuft that is arranged most central inthe plurality of bristle tuft is the shortest.

Similar effects also appear regarding the size of a bristle tuft or theform of a bristle tuft. In larger bristle tufts the central filamentsare shielded against the energy during the fusing process. Said effectis further influenced by the form of the bristle tuft as the shieldingeffect is larger for round bristle tufts than for elongatedstripe-shaped bristle tufts. Without being bound by a theory it isbelieved that the formation of a central depression in the plane duringfuse ball formation is based on the shielding of the inner bristlefilaments by the outer bristle filaments. Accordingly, larger bristletufts and/or bristle tufts with a larger cross-section are arranged witha smaller distance to the energy source than smaller bristle tuftsand/or bristle tufts with a smaller cross-section. The distance betweenthe energy source and the bristle tuft ends of bristle tufts decreaseswith increasing cross-section of the bristle tuft in a fusing positionaccording to the method as disclosed herein.

In addition or alternatively, the fusing process is also influenced bythe properties of the bristle filaments, such as material, diameter,cross-section, shape, color, of the bristle filament or the presence offurther additives in the bristle filament. For example, in a fusingposition the distance between the energy source, in particular thethermal energy source and the bristle tuft ends is adjusted according tothe material of the bristle tuft, wherein preferably the distance islarger for bristle tufts comprising bristle filaments made frompolyamide (PA), in particular nylon, polyamide 6.6, polyamide 6.10, orpolyamide 6.12, than for bristle tufts comprising filaments made ofpolybutylene terephthalate (PBT) or polyethylene terephthalate (PET).

In addition or alternatively, the fusing process is also slightlyinfluenced by the color of the bristle filaments. For example, thedistance between the energy source and the bristle tuft ends of bristletufts comprising green bristle filaments may be chosen larger than thedistance between the energy source and the bristle tuft ends of bristletufts comprising filaments of any other color.

In addition or alternatively, the fusing process may also be influencedby the size, in particular by the diameter and/or cross-section of thebristle filaments. Without being bound by a theory it is believed thate.g. smaller bristle filaments melt faster than larger bristle filamentsand/or X-shaped bristle filaments melt faster than round filaments. Forexample according to the method as disclosed herein, in a fusingposition the distance between the energy source, in particular thethermal energy source and the bristle tuft ends of bristle tuftscomprising bristle filaments with a smaller diameter and/orcross-section may be larger than the distance between the energy sourceand the bristle tuft ends of bristle tufts comprising bristle filamentswith a larger diameter and/or cross-section, preferably wherein thedistance may be decreased with increasing bristle filament diameterand/or cross-section, more preferred wherein the distance may bedecreased from bristle filament diameter of about 2 mil (0.0508 mm) toabout 9 mil (0.2286 mm). In addition or alternatively, in a fusingposition the distance between the energy source and the bristle tuftends of bristle tufts comprising bristle filaments with an X-shapeddiameter may be larger than the distance between the energy source andthe bristle tuft ends of bristle tufts comprising bristle filaments witha round diameter.

Another property which may influence the fusing process and thus mayinfluence the fusing position of the bristle tufts is the presence orabsence of additives in the bristle filaments. Additives may decelerates and/or accelerate the fusing process by absorbing or reflecting thethermal energy using process. For example, in a fusing position thedistance between the energy source, e.g. the thermal energy source andthe bristle tuft ends comprising bristle filaments comprising anadditive, e.g. clay or titanium dioxide is shorter than the distancebetween the energy source and the bristle tuft ends of bristle tuftscomprising filaments without said additive.

The influences of all properties of the bristle tufts and bristlefilaments as disclosed above may compensate each other or may intensifyeach other. For example, bristle tufts with a smaller cross-section thatare located in the middle of a bristle field may undergo a similarfusing process than bristle tufts with a larger cross-section that arelocated at the outside of a bristle field. Thus, according to the methodas disclosed herein all properties of a bristle tuft are considered byadjusting the distance of the end of said bristle tuft to the energysource. Preferably, the influence of some properties is assessed largerthan the influence of other properties. In a preferred embodiment of themethod as disclosed herein, the distance between the bristle tuft endand the energy source, e.g. the thermal energy source is adjustedaccording to the size and/or cross-section of the bristle tuft, theposition of the bristle tuft in the bristle field or a combinationthereof, more preferred the distance between the bristle tuft end andthe energy source, e.g. the thermal energy source is adjusted accordingto the position of the bristle tuft in the bristle field.

Any suitable energy source that is capable of producing the requiredamount of energy can be used for the fusing process as disclosed herein.For example, a thermal energy source may be used, the thermal energysource is a heater, preferably a convection type heater, a thermalradiation type heater, an infra-red radiation lamp or the like.Alternatively, the heater may be a heating plate, more preferred whereinthe heating plate is at least partly made of a conductive material foremitting thermal radiation when an electric current flow through theconductive material. Suitable heating sources are for example disclosedin WO2015/094991A1 which is incorporated herein by reference. Forexample, the thermal energy source may comprise a heating plate that isat least partly made of a conductive material for emitting thermalradiation when an electric current flow through the conductive material.Said heating plate may be structured such that at least two heatingsectors each comprising conductive material are formed that areseparated from each other by at least one separation sector arranged foremitting at least less thermal radiation then the heating sectors andthat each heating sector has a heating surface on a heating side of theheating plate, where each of the heating surfaces has an area in a rangeof between about 0.25 mm² to about 250 mm², in particular wherein atleast one of the heating surfaces has an area below 100 mm².

The heating surfaces can be heated to a degree that the thermalradiation is sufficient to melt the bristle tuft ends provided at acertain distance in an emission direction. The distance between thebristle tuft ends and the heating surfaces during the fusing process maylie in a range of from about 0.05 mm and about 5 mm, preferably in arange of from about 0.1 mm and about 2 mm and is adapted according tothe properties of the bristle tuft as disclosed herein. The temperatureof the heating surfaces may be in a range of about 500 degrees Celsiusto about 800 degrees Celsius and the application time of thermal energyfrom the thermal energy source during fusing might be in the range from1 to 15 sec, preferably from 2 to 12 sec, more preferred from 3 to 10sec, more preferred from 4 to 8 sec, more preferred from 5 to 7 sec. Asuitable flow of thermal energy (Φ) from the thermal energy source tothe at least two bristle tuft ends located in the hole perforation platewherein the Temperature in ° C. measured with emissivity 0.88 is in therange from 500° C. to 1000° C., preferably 600° C. to 900° C., morepreferred from 650° C. to 850° C.

The heating surfaces of the heating sectors of the heating plate may bemade of a conductive material having a higher resistance than theresistance of a conducting material forming the at least one separationsector at least partly bordering the heating sectors. For example, thismay be a layer of conductive material at the location of the heatingsectors that is thinner than the layer thickness of a conductivematerial forming at least partly the separation sector and/or this maybe a higher resistivity conductive material used to realize the heatingsectors in comparison to the conductive material forming at least partlythe separation area. Sufficient thermal radiation will be emitted when asufficient electric current is flowing through the heating sectors, i.e.electric currents of typically up to 200 Ampere. The layer thickness ofthe conductive material forming the heating sectors may be for exampleabout or below 1.0 mm, in particular below 900 μm, below 800 μm, below700 μm, below 600 μm, below 500 μm, below 400 μm, below 300 μm, below200 μm, or below 100 μm, preferably in a range of 250 μm to 750 μm or ina range of about 400 μm to about 600 μm. The layer thickness ofconductive material in the separation sector may be above 1.0 mm, inparticular above 1.5 mm, above 2.0 mm, above 3.0 mm, above 4.0 mm, above5.0 mm, or above 10 mm.

As a heating sector a structured portion of the heating plate isunderstood herein comprising conductive material, which structuredportion has a heating surface on the heating side of the heating platethat tends to emit a higher amount of thermal radiation than surfaceareas of the separation sector that at least partly borders therespective at least two heating sectors, in particular as the heatingsector comprises conductive material having a higher resistance thanconductive material in adjacent (i.e. bordering) areas of the heatingplate or because the heating sector is embedded in an isolatingmaterial.

Electrical resistivity p (also known as resistivity, specific electricalresistance, or volume resistivity) quantifies how strongly a givenmaterial opposes the flow of electric current. A low resistivityindicates a material that readily allows the movement of electriccharge. For example, 18% chromium/8% nickel austenitic stainless steelhas a resistivity of ρ_(steel)=6.9·10⁻⁷ Ωm, copper ofρ_(copper)=1.68·10⁻⁸ Ωm, PET (polyethylene terephthalate) ofρ_(PET)=1.0·10²¹ Ωm (all values given for a temperature of 20° Celsius).Resistivity is a material property. The resistance R of a piece ofresistive material having a length 1 and a cross sectional area Aagainst flow of electric current between its both ends in lengthdirection is given by R=ρ·l/A. Thus, the resistance of a uniform pieceof material of given length can be increased by reducing itscross-sectional area, as is generally known.

Perfect isolator materials do not exist, however “conductive material”shall mean a material having a resistivity below ρ=1.0 Ωm (inparticular, this limit may be set to below ρ=1.0·10⁻¹ Ωm) and “isolatingmaterial” shall mean a material having a resistivity above ρ=1.0 Ωm (inparticular, this limit may be set to above ρ=1.0·10³ Ωm). Metals(allowing free electron flow) such as steel, copper, silver, gold, ironand metal alloys etc. are good conducting materials. Other conductingmaterials include amorphous carbon, conductive ceramics such as ITO andconductive polymers such as PEDOT:PSS. Conductive materials that are inparticular suitable within the scope of the present disclosure are thoseconductors that are thermally stable at the above-mentioned temperaturesof about 500 degrees Celsius to about 800 degrees Celsius.

Many metals such as steel, copper, aluminum, silver, many metal alloysincluding iron-based alloys or copper-based alloys such as brass, bronzeor Beryllium copper (ASTM B194, B196, B197) etc. are thermally stable(i.e. do not notably deform or melt or otherwise degrade so that thematerial is usable for an industrially sensible period) within themeaning of the present disclosure. Good isolator materials are glass,paper, dry wood, Teflon, PET, hard rubber, rubberlike polymers,isolating ceramics such as aluminum oxide or steatite and many plasticsetc.

The passage of electric current through a conductor releases thermalenergy by a process known as resistive heating (or ohmic heating orJoule heating). Said resistive heating leads to emission of thermalradiation, in particular infrared radiation that is absorbed by the endsof the filaments in a sufficient amount so that the thermoplasticmaterial of the exposed ends of the bristle tufts melts and the moltenmaterial forms a fuse ball structure as is has been discussed in detailbefore. Fusing of bristle tufts ends as disclosed herein can beperformed horizontally (i.e. the tufts are arranged essentially parallelto the direction of earth gravity) but as well as vertically (i.e. wherethe tufts are substantially inclined against the direction of earthgravity, in particular where the tufts are arranged essentiallyperpendicular to the direction of earth gravity). Vertical fusing willbe in particular possible, if the applied thermal energy is adapted tothe individual properties of the bristle tufts as disclosed herein. Themolten bristle tuft ends melt very fast and also solidify very fast whenthe source of thermal radiation is moved away so that essentially no“noses” of dripping plastic melt is generated. Fusing technologiesapplying more thermal energy than those needed for the formation of thefuse ball heat up for example the whole environment such that at leastgeneration of the mentioned noses during vertical fusing can hardly beavoided. Due to the defined heating of the bristle tuft ends asdisclosed herein the volume of material that is molten is lower than inthe normal fusing process and the surface tension of the molten materialis thus higher and effectively reduces the generation of noses or evendripping material. In addition, the heating process can be further costoptimized by using different heating sectors, so that the heatingsurfaces selectively emit different amounts of thermal radiation duringoperation of the device. The area of the heating surface of each of theheating sectors may lie in a range of about 0.25 mm² and about 250 mm²,in particular in a range of about 0.5 mm² and about 100 mm², wherefurther in particular the upper limit may be smaller, such as about 90mm², 80 mm², 70 mm², 60 mm², 50 mm², 40 mm², 30 mm², 20 mm², 10 mm², 5mm², 4 mm², 3 mm², or 2 mm². A typical cylindrical tuft as used in manyof today's toothbrushes may has a diameter in the range of between about0.5 mm to about 2.5 mm, in particular in the range of between about 1.0mm to about 2.0 mm, further in particular in the range of between about1.3 mm to about 1.8 mm. As an example, a circular tuft having a diameterof 1 mm has an area of about 0.785 mm². Some toothbrushes comprise largesized single tufts such as the Oral-B CrossAction® toothbrush, which hasa large size single bristle tuft at its foremost end having an area ofabout 28 mm² (30 mm² may then be considered as an appropriate upperlimit). Obviously, even larger single bristle tufts can be contemplated(50 mm² may then be considered an appropriate upper limit). Theindividual bristle tufts are each arranged with a distance to eachother, as otherwise they would form a single tuft with densely arrangedfilaments. The bristle tufts are arranged with a distance to allow thefree filament ends of the final toothbrush to move when applied with aforce against a tooth surface. Typical distance between neighboringtufts of a tuft field of a toothbrush may lie in a range of about 0.2 mmto about 5.0 mm, in particular in a range of about 0.5 mm and about 2.0mm. In some of today's toothbrushes a distance between neighboring tuftsof about 0.8 mm to about 1.6 mm is employed.

Higher thermal emission of the heating surfaces may be achieved by adifferent average profile roughness Ra on the heating surfaces than onthe bordering surfaces made of conductive material of the separationsectors. Typical values for the average profile roughness of the heatingsurfaces are Ra≥20 μm, in particular Ra≥25 μm (an upper limit of Ra≤200μm, in particular of Ra≤200 μm and further in particular of Ra≤50 μm maybe employed). Typical values for the average profile roughness of thesurface of the separation sector(s) are Ra≤10 μm, in particular Ra≤5 μm,further in particular Ra≤2.0 μm. Typical polished surfaces have anaverage profile roughness of Ra≤1.0 μm (where finish grinding results inan average profile roughness of Ra≤0.2 μm).

The heating surface may be a non-flat surface, e.g. may be concavelyformed so that the thermal radiation will be more focused than with aflat heating surface. Generally, the heating plate may be made fromsintered, in particular laser sintered material, in particularconductive material, even though the heating plate may also compriseisolating material.

After formation of the fuse balls the at least two bristle tufts aretransferred to a subsequent process position, wherein in the subsequentprocess position the distance of the bottom edge of the fuse ball of atleast one bristle tuft to the front surface of the hole perforationplate is different to the distance of the bottom edge of said fuse ballof said bristle tuft to the front surface of the hole perforation platein the fusing position, wherein the subsequent process position might bee.g. the molding position. Preferably, the distance between the bottomedge of the fuse ball and the front surface of the hole perforationplate of at least one bristle tuft in the fusing position is larger orshorter, preferably larger than the distance between the bottom edge ofthe fuse ball and the front surface of the hole perforation plate ofsaid at least one bristle tuft in the subsequent process position. Theterm “bottom edge of a fuse ball” as used herein shall be understood asthe position at the bristle filaments in a bristle tuft where theamendment of the bristle filament material caused by the energy, inparticular thermal energy applied during the fusing process, i.e.softening or melting of the material of the bristle filament, ends.

That means after the fusing process the position of the bristle tufts inthe hole perforation plate may be amended again, wherein the position ofthe bristle tufts is adjusted to the requirements of the subsequentprocesses. For example, the distance between the bottom edge of the fuseball and the front surface of the hole perforation plate of at least onebristle tuft in the fusing position is larger or shorter, than thedistance between the bottom edge of said fuse ball and the front surfaceof the hole perforation plate of said at least one bristle tuft in thesubsequent process position. For example, the subsequent process mightbe the over-molding of the fuse balls to form a brush head at leastpartially. If the subsequent process position is adjusted according tothe molding process a larger distance between the bottom edge of thefuse ball and the front surface of the hole perforation plate might beadvantages in order to have more material flowing around the fuse balland fixing the bristle tuft more tightly in the brush head to be formed.In addition or alternatively, a smaller distance between the bottom edgeof the fuse ball and the front surface of the hole perforation platemight be advantages in order to produce small brush heads and/or togenerate free space in the brush head above the fuse balls. Said freespace may be needed to include other features of a brush head, such aselastomeric cleaning elements, or gearing or coupling elements which areneeded for brush heads of electric toothbrushes. A suitable distancebetween the bottom edge of the bristle tuft end and the front surface ofthe hole perforation plate of the at least two bristle tufts in themolding position is in the range from 0.2 to 3 mm, preferably from 0.3to 2.5 mm, more preferred from 0.4 to 2 mm, more preferred from 0.5 to1.5 mm, more preferred from 0.6 to 1.2 mm.

Other subsequent process steps, such as reviewing or checking stepsand/or molding steps, that provide elastomeric cleaning elements intothe perforation plate may be included optionally in the method asdisclosed herein. Suitable reviewing or checking steps may includechecking and confirming the correct number, diameter and/or color offilaments in the individual hole of the perforation plate; checking andconfirming correct position of bristle tufts and/or elastomeric elementsin the holes of the perforation plate; checking the presence and qualityof the fuse ball of a bristle tufts, and/or combinations thereof. Thequality check of a fuse ball may comprise dislocating the fuse ball fromthe perforation plate in order to visually inspect the fuse ball by top,down and side views for checking form and size of the fuse ball andwhether all filaments are included completely. Finally, the bristletufts are arranged in the molding position, wherein the distance betweenthe bottom edge of the fuse ball and the front surface of the holeperforation plate is adjusted according to the requirements of thesubsequent molding process, where according to the method as disclosedherein said molding position of at least one bristle tuft differs fromthe fusing position of said bristle tuft.

After the bristle tufts are arranged in the molding position the fuseballs of the at least two bristle tufts are over-molded with plasticmaterial, whereby a brush head or the part thereof is formed. Therefore,a mold is formed, wherein the hole perforation plate forms one part ofthe mold. The mold is formed in such that the fuse balls are located inthe hollow formed by the mold without having contact to any of the innersurfaces of the mold so that the fuse balls can be embedded into thematerial to be injected completely when the brush head or the partthereof is formed. Suitable materials for forming the brush head or thepart thereof are hard plastic materials. The Shore D hardness of the“hard plastic” material as understood herein may be in the range fromabout 30 to about 90, in particular in the range from about 40 to about80, more particular in the range from about 50 to about 80, even moreparticular in the range from about 65 to about 75. Suitable materialswhich may be used as hard plastic material may be for examplepolypropylene (PP), polyethylene (PE), polyoxymethylene (POM),polyethylene terephthalate (PET), a polyamide (PA), or a blend or amixture comprising polypropylene (PP), polyethylene (PE),polyoxymethylene (POM), polyethylene terephthalate (PET) or a polyamide(PA).

The brush head may comprise further elements, such as chemical releasingelements or elastomeric elements. A “chemical releasing element” asunderstood herein is any element which releases chemical substancesduring use, in contact with water and/or saliva and/or after mechanicalinfluence by the bristle filaments during brushing. Suitable chemicalreleasing elements are for example pads or reservoirs which are filledwith or comprise chemical actives. Suitable chemical actives which mightbe released may be for example, anti-sensitivity chemicals, pain-reliefchemicals, wound-healing chemicals, anti-inflammation chemicals,flavoring components, anti-tartar chemicals, whitening chemicals,anti-bacterials, anti-erosion chemicals or a mixture thereof.

An “elastomeric element” as understood herein is any cleaning elementthat is not a bristle filament or a bristle tuft. Elastomeric elementsmay be formed e.g. from soft plastic material. The Shore A hardness of“soft plastic” material as understood herein may be in the range fromabout 10 to about 80, in particular in the range from about 20 to about70, more particular in the range from about 30 to about 60, even moreparticular from about 30 to about 40. The Shore A hardness of the softplastic material is adapted to the geometry used for the elastomericelement. Thinner geometric elements may be produced from a materialhaving a greater Shore A hardness compared to thicker elements and viceversa. The choice of the soft plastic material also depends on thelength of the element formed. In principle, longer geometric elementsmay be manufactured from a soft plastic material having a greater ShoreA hardness compared to shorter elements. Suitable materials which may beused as soft plastic material may be for example rubber, thermoplasticelastomer (TPE), polyethylene (PE), polypropylene (PP), Polyoxymethylene(POM) or a blend or a mixture thereof. Materials which show elastomericproperties, such as TPE, are preferably used as soft plastic materialsherein. The soft plastic material may have any geometric form, forexample, a nub, a pin, a fin, a wall, a bar, a gutter, a curve, acircle, a lamella, a textured element, a polishing element such as, forexample, a polishing cup, or a tongue cleaning element or a combinationthereof.

The elastomeric element may be produced before and/or may be providedtogether with bristle tuft(s) and may be over-molded with the materialused to form the brush head or a part thereof. In addition oralternatively, the brush head or the part thereof may comprise holeswhich are filed with elastomeric material in a subsequent process stepin order to form elastomeric elements. Preferably, elastomeric elementsthat are included into a bristle field are produced and/or providedbefore and/or together with the bristle tufts. In addition oralternatively, elastomeric elements that are positioned at the outlineand/or at the backside of a brush head, e.g. elements intended to cleanthe gum line or the tongue are preferably produced and/or provided afterthe bristle field. Independently from the process step used, a physicalconnection is built between the elastomeric element and the brush head.The toothbrush may be for example a manual toothbrush or a replacementbrush for an electrical toothbrush comprising a brush head as disclosedherein providing one or more cleaning element(s), a handle and a neckconnecting the brush head and the handle to each other, wherein the oneor more cleaning element(s) may comprise one or more elastomericelements and one or more bristle tuft(s). The method disclosed hereinallows high design flexibility and makes handling ofnon-bristle-tuft-cleaning elements as easy as bristle-tuft cleaningelements. Handling of elastomeric elements is usually challenging due tothe fact that the elastomeric elements are difficult to grip, could bestrongly influenced by electrostatic forces and are difficult to handledue to their elastomeric properties. Theses handling problems aredecreased, if elastomeric elements are directly formed in the holeperforation plate. By the methods disclosed herein bristle tuft cleaningelements and elastomeric elements are handled in a similar mannerthereby making toothbrush manufacturing more efficient. In addition oralternatively, the present method may also ease handling of advancedfilament types, such as super-thin filaments which are taperedchemically or mechanically in anchor-free manufacturing techniques.

After the intended cleaning elements are all placed in the holeperforation plate a mold cavity is formed comprising the holeperforation plate as the first mold half and at least one second moldhalf. Then a plastic material which shall form the brush head or a partthereof is injected into the mold cavity. Thereby the fuse balls of theone or more bristle tuft(s) and the optional elastomeric element areover-molded with the molten plastic material. Thereby, the fuse ballsare embedded into the plastic material and undercuts are formed so thatthe bristle tufts are secured against pulling forces. For example, themolten material of the cleaning element carrier may flow around the tuftends of the bristle tufts forming small balls or plates or any geometricprotrusion of the elastomeric element may be embedded into the moltenmaterial forming the brush head or a part thereof. Preferably, the partthat is formed from the molten material is a cleaning element carrier.The cleaning element carrier comprises a front surface, a back surfaceand a thickness, wherein the cleaning element carrier is at least thickenough to embed the one or more fuse ball(s) completely in the cleaningelement carrier. A suitable thickness of the cleaning element carriermay be in the range of from about from 2.0 mm to 4.0 mm, preferably inthe range of from 2.2 mm to 4.0 mm, more preferably in the range of from2.5 mm to 3.5 mm. The bristle filaments protrude from the front surfaceof the cleaning element carrier and at least two fuse balls arepreferably located at different levels in the cleaning element carrier.The cleaning element carrier might be manufactured from any suitableplastic material, in particular from any plastic material which can beprocessed in a molten state. Suitable material comprises polyethylene(PE), polypropylene (PP), Polyoxymethylene (POM), thermoplasticelastomers (TPE) or a blend or a mixture thereof, wherein the differentmaterials show different advantages and are chosen accordingly. Forexample polyoxymethylene is a harder material showing a higherresistance during use, but is more difficult to process during injectionmolding; in contrast, polypropylene is less hard and resistant, but alsoless expensive and easier to process during injection molding. In thepresent invention the material of the cleaning element carrier ispreferably made from polypropylene.

The cleaning element carrier may further comprise an edge at theperiphery of the back surface. That means, the cleaning element carriermay further comprise a central depression in the back surface,preferably a central depression in the range of from 0.1 mm to 3 mm,more preferred in the range on from 0.5 mm to 2.5 mm, more preferred inthe range of from 1 mm to 2 mm, more preferred in the range of from 1.5to 1.8 mm. The central depression may cover at least 70% of the area ofthe back surface, preferably at least 80% of the area of the backsurface, more preferred at least 85% of the area of the back surface,more preferred at least 90% of the area of the back surface, morepreferred from 90% to 98% of the area of the back surface. For example,a drive part might be located in the first central depression. Inaddition, the cleaning element carrier may further comprise a secondcentral depression, in the back surface, wherein the optional secondcentral depression is preferably in the range of from 0.1 mm to 2 mm,more preferred in the range on from 0.1 mm to 1.6 mm, more preferred inthe range of from 0.2 mm to 0.8 mm. The second depression(s), inparticular the second central depression(s) may cover at least 30% ofthe area of the first depression, preferably at least 40% of the area ofthe first depression, more preferred from 40% to 50% of the area of thefirst depression. For example, distribution channels or a soft plasticmaterial layer for soft plastic cleaning elements might be located inthe second central depression.

In addition or alternatively, a cover might be located inside the edgeand might cover the depressions of the cleaning element carrier, whereinthe surface of the cover forms preferably a planar surface with the edgeof the cleaning element carrier. The cover may be produced separately ormight be formed directly onto the cleaning element carrier, e.g. byinjection molding. For example, the material of the cover might comprisepolyethylene (PE), polypropylene (PP), polyoxymethylene (POM),thermoplastic elastomers (TPE) or a blend or a mixture thereof. Thematerial might be molten and might be injected directly onto thecleaning element carrier. Preferably the material of the cover might beidentical to the material that is used for the cleaning element carrier.If both materials are identical an optimal bond between the cleaningelement carrier and the cover is achieved. Preferably, polypropylene(PP) is used as material of the cover. In an alternatively preferredembodiment, the elastomeric cleaning elements and the cover are madefrom the same material, in particular are made from thermoplasticelastomers (TPE). The color of the material of the cover might beidentical or different to the color of the material of the cleaningelement carrier.

In addition or alternatively, the cleaning element carrier mightcomprise one or more slots, which are suitable to receive one or moreelastomeric elements. The slots might be of any geometrical form andshape and the form and shape of the one or more slot(s) might be adaptedaccording to the form and shape of the elastomeric elements. If moreelastomeric elements are included into the cleaning element carrier, theelastomeric elements may be identical to each other or may differ inform and shape. If more elastomeric elements made from the same materialare included into the cleaning element carrier the back surface of thecleaning element carrier might comprise distribution channels whichconnect the one or more slot(s) to each other so that the elastomericmaterial can be distributed over the cleaning element carrier and allelastomeric elements can be produced in one process step. That meansthat the elastomeric elements are connected to each other viaelastomeric material located in the distribution channels. In contrast,different elastomeric elements can be produced independently from eachother. Suitable material which can be used for the elastomeric elementscomprise rubber, thermoplastic elastomer (TPE), or a blend of mixturethereof, preferably used are thermoplastic elastomer (TPE) materials.

The cleaning element carrier comprising the bristle tufts and theoptional elastomeric elements represents the central part, namely thecleaning part of a toothbrush head. The cleaning element carrier mightbe included into a toothbrush head of a replacement brush head for anelectric toothbrush or might be included into a toothbrush head of amanual toothbrush. For example, the cleaning element carrier might beplaced into a mold and might be over-molded with molten plastic materialthereby forming the toothbrush, a replacement brush head for anelectrical toothbrush or a part thereof. That means, brush heads, inparticular toothbrush heads or parts thereof, as well as toothbrushescomprising said brush heads or parts thereof which are preferablyproduced by the method as disclosed herein can be used for manufacturingany kind of manual toothbrush or any kind of replacement brush forelectric toothbrushes. Thus, the present disclosure further provides abrush, in particular a toothbrush comprising a cleaning element carrierproviding cleaning elements as disclosed herein.

In the following, a detailed description of several example embodimentswill be given. It is noted that all features described in the presentdisclosure, whether they are disclosed in the previous description ofmore general embodiments or in the following description of exampleembodiments of the devices or the method, even though they may bedescribed in the context of a particular embodiment, are of course meantto be disclosed as individual features that can be combined with allother disclosed features as long as this would not contradict the gistand scope of the present disclosure. In particular, all featuresdisclosed for either one of the devices or a part thereof or disclosedtogether with the method may also be combined with and/or applied to theother parts of the devices or a part thereof, if applicable and viceversa.

FIG. 1A shows an example embodiment of a cleaning element carrier 30.The cleaning element carrier 30 comprises a front surface 31, a backsurface 32 and a thickness T. A suitable thickness of a cleaning elementcarrier 30 as disclosed herein is in the range from 2.5 mm to 3.5 mm.The cleaning element carrier 30 shown is a disc, but non-round shapesare also possible. The cleaning element carrier 30 comprises at leastone protrusion 37, wherein the protrusion 37 is located centrally at thefront surface 31. The central protrusion 37 covers at least 10% of thewhole front surface 31, preferably 15%, more preferred 20% of the wholefront surface 31. The size of the central protrusion 37 in % of thewhole front surface 31 depends on the tuft design. The centralprotrusion 37 protrudes about 0.4 mm from the front surface 31. Thecentral protrusion 37 preferably ends between two tufts, but in certainembodiments the central protrusion 37 may also end within one or moretufts.

FIG. 1B shows another example embodiment of a cleaning element carrier30 comprising a front surface 31, a back surface 32 and a thickness T. Asuitable thickness of a cleaning element carrier 30 as disclosed hereinis in the range from 2.5 mm to 3.5 mm. The cleaning element carrier 30comprises at least one protrusion 37, which is located centrally at thefront surface 31 and a central depression at the back surface 32. Thecentral depression 35 covers at least 70% of the back surface 32 so thatan edge 34 is formed in the periphery. The edge 34 may be about 0.6 mmto 1.2 mm thick, but smaller edges may be also possible as long as anedge is formed which is stable during manufacturing process. The centralprotrusion 37 covers at least 10% of the whole front surface 31,preferably 15%, more preferred 20% of the whole front surface 31.

FIG. 1C shows an example embodiment of a part 10 of a brush head. Thepart 10 shown in side view comprises a cleaning element carrier 30 witha front surface 31 and a back surface 32 and several bristle tufts 20.Seven bristle tufts 20 can be seen, wherein each bristle tuft 20comprises several filaments 22. The bristle tufts 20 protrude from thefront surface 31 of the cleaning element carrier 30 and the ends 26 ofthe filaments 22 that are intended for cleaning are end-rounded in orderto ensure a save use. At the opposite end of the filaments 22 a fuseball (not shown) is formed which is embedded into the cleaning elementcarrier 30. The part 10 of a brush head further comprises twoelastomeric cleaning elements 40 made from a thermoplastic elastomer(TPE).

FIG. 1D shows a cross-sectional view of another example embodiment of apart 10 of a brush head comprising a cleaning element carrier 30 withseveral bristle tufts 20 forming a bristle field 28. Three differenttypes of bristle tufts 20 are shown (20 a, 20 b, 20 c) which can differin number, color, length and/or material of the individual filaments.The bristle tufts 20 c is a tuft-in-tuft embodiment, wherein the innercentral tuft protrudes from the peripheral tuft. The cleaning elementcarrier 30 comprises at least one protrusion 37, which is locatedcentrally at the front surface 31 and a central depression at the backsurface 32. The bristle tufts 20 protrude from the front surface 31 ofthe cleaning element carrier 30 and the ends 26 of the filaments formingthe bristle tufts 20 that are intended for cleaning are end-rounded inorder to ensure a save use. At the opposite end of the bristle tufts 20a fuse ball 24 is formed which is securely embedded into the cleaningelement carrier 30. The back surface 32 of the cleaning element carrier30 comprises a central depression 35, wherein the central depression 35covers at least 70% of the back surface 32 so that an edge 34 is formedin the periphery. The edge 34 may be about 0.6 mm thick, but smalleredges may be also possible as long as an edge is formed which is stableduring manufacturing process. The front surface 31 comprises a centralprotrusion 37, wherein the area of the cleaning element carrier coveredby the protrusion 37 is smaller than the area of the cleaning elementcarrier covered by the depression 35 so that the protrusion 37 is notrecognizable by the user of the brush head. The protrusion 37 may coverat least 10% of the front surface 31 and may be helpful to increase thethickness T of the cleaning element carrier 30 locally. A standardthickness T of the cleaning element carrier 30 in the periphery is inthe range from 2.5 mm to 3.5 mm, wherein the central depression 35 maydecrease the thickness by about 1.5 mm Thus, it might be advantageous toincrease the thickness T again by a protrusion 37 at the front surface31. An increase of the thickness T by a protrusion 37 might be about 0.4mm and might help to securely embedded the bristle tufts 20 in themiddle of the cleaning element carrier 30.

FIG. 2A shows a cross-sectional view of an example embodiment of acleaning element carrier 30 comprising voids 38 which can be filled withcleaning elements. The front surface 31 of the cleaning element carrier30 comprises a central protrusion 37 which covers at least 20% of thefront surface 31. The back surface 32 of the cleaning element carrier 30comprises a central depression 35 which covers at least 70% of the backsurface 32 so that an edge 34 is formed in the periphery. In the middleof the central depression 35 a second depression 36 is shown whichcovers about 10% of the back surface 32. The cleaning element carrier 30shown in FIG. 2A is a disc, but non-round shapes are also possible. Theback surface 32 further comprises a network of grooves 39 that areconnected to each other and which are located in the area of thedepression 35. The grooves 39 may form any network that is suitable toconnect the voids 38 so that at each end of the grooves 39 a void 38 islocated in the cleaning element carrier 30 which can be filled withcleaning elements. FIG. 2B shows the cleaning element carrier 30 shownin FIG. 2A, wherein the voids 38 are filled with elastomeric cleaningelements 40. The elastomeric material for the elastomeric cleaningelements 40 was added into the grooves 39 and distributed over thenetwork so that an elastomeric connection 39 a is formed therein and allelastomeric cleaning elements 40 are formed together. Thus, theelastomeric cleaning elements 40 are connected to each other via theelastomeric connection 39 a at the back surface 32 of the cleaningelement carrier 30.

FIG. 2C shows a cross-sectional view of the example embodiment of acleaning element carrier 30 comprising a central depression 35 at theback surface 32 and a central protrusion 37 at the front surface 31. Adrive part 44 is placed in the central depression. FIG. 2D shows across-sectional view of the example embodiment already shown in FIG. 2C,wherein the drive part 44 is mounted to the cleaning element carrier 30with a cover 46. The cover 46 is located inside the central depression35, wherein the back surface 47 of the cover 46 forms a planar surfacewith the edge 34. The material of the cover 46 is selected frompolyethylene (PE), polypropylene (PP), Polyoxymethylene (POM) or a blendor a mixture thereof, preferably the material of the cover 46 isidentical to the material of the cleaning element carrier 30 and thecover 46 is formed by injection molding directly into the depression 35of the cleaning element carrier 30. Thus, the cover 46 and the cleaningelement carrier 30 are connected to each other and the drive part 44 issecurely mounted. The color of the cover 46 is preferably different fromthe color of the cleaning element carrier 30.

FIG. 2C shows a cross-sectional view of the example embodiment of acleaning element carrier 30 comprising a central depression 35 at theback surface 32 and a central protrusion 37 at the front surface 31. Astandard thickness T of the cleaning element carrier 30 in the peripheryis in the range from 2.5 mm to 3.5 mm, wherein the central depression 35decreases the thickness by about 1.5 mm A drive part 44 is placed in thecentral depression and covered with a cover 46. The cover 46 is locatedinside the central depression 35, wherein the back surface 47 of thecover 46 forms a planar surface with the edge 34. The cover 46 ispreferably made of the same material than the cleaning element carrier30 and the cover 46 is formed by injection molding directly into thedepression 35 of the cleaning element carrier 30. Several bristle tufts20 and elastomeric cleaning elements 40 protrude from the front surface31 of the cleaning element carrier. Seven bristle tufts 20 can be seen,wherein each bristle tuft 20 differs in at least one property from theother bristle tufts 20. For example bristle tufts 20 a and 20 b differin the position of the bristle tuft 20 in the cleaning element carrier30. The central bristle tufts 20 c comprise more bristle filaments andis a tuft-in-tuft embodiment comprising an inner tuft that protrudesfrom the peripheral tuft. In addition the bristle filaments of thebristle tufts 20 a, 20 b, 20 c may further differ regarding material,color or size of the bristle tuft. The elastomeric cleaning elements 40are made from a thermoplastic elastomer (TPE).

FIGS. 3A-33I show a schematic method which can be used to produce thecleaning element carrier 30 as disclosed herein. FIG. 3A shows a holeperforation plate 60 which comprises a front surface 61, a back surface62, a thickness D and a plurality of holes 70, wherein the plurality ofholes 70 is shaped and distributed in the hole perforation plate 60according to the desired bristle field 28 of the brush head to beproduced. The thickness D is adapted to the length of the bristle tufts20 which shall be placed in the holes 70 (FIG. 3B). Thus, the holeperforation plate 60 is thick enough that the filaments 22 of thebristle tufts 20 are stabilized and protected during the manufacturingsteps, but thin enough that the bristle tufts 20 can still be handled. Asuitable thickness D for the hole perforation plate 60 is from 6 mm to14 mm. The holes 70 are adapted to size and shape of the bristle tufts20 that shall be placed therein. For example, bristle tuft 20 a islarger than bristle tuft 20 b, thus the holes 70 are differentaccordingly.

In FIG. 3C the hole perforation plate 60 was rotated by 90°. The bristletufts 20 protrude from the hole perforation plate 60 at both sides. Oneend 26 of the bristle tufts 20 is intended for cleaning and thus, isend-rounded and comprises a smooth surface. The opposite end 23 of thebristle tufts 20 is intended for fusing. The fusing of the ends 23 isperformed with a thermal energy source 80 which is approached to theends 23. Due to the different properties of the bristle tufts 20 a, 20 bthe ends 23 melt differently, i.e. require different amounts of thermalenergy to melt. For example, bristle tuft 20 a is significantly largerthan bristle tuft 20 b so that bristle tuft 20 a requires more thermalenergy to melt. Thus, the distance between end 23 of bristle tuft 20 aand the thermal energy source 80 is smaller than the distance betweenend 23 of bristle tuft 20 b and the thermal energy source 80. If thethermal energy is applied the ends 23 melt and form fuse balls 24 (FIG.3D) which are similar compared to each other due to the differentdistances to the thermal energy source 80. Thereby, the distance of thebottom edge 25 of the fuse ball 24 of a first bristle tuft 20 a to thefront surface 61 is different to the distance of the bottom edge 25 ofthe fuse ball 24 of a second bristle tuft 20 b to the front surface 61.For example, bristle tuft 20 b which is located in the middle of thebristle filed is shielded against the thermal energy from the thermalenergy source 80 by its neighboring bristle tufts 20. Thus, bristle tuft20 b is arranged closer to the thermal energy source 80.

After the fuse balls 24 are formed the bristle tufts 20 are arranged inthe hole perforation plate 60 according to the arrangement of thebristle tufts 20 in the bristle field 28 that shall be produced (FIG.3E). That means, the distance between the fuse balls 24 and the holeperforation plate 60 during fusing can be different than for thesubsequent process steps such as molding. The position of the bristletufts 20 in the hole perforation plate 60 in the molding position isbased on the position of the ends 26 intended for cleaning in thebristle field 28. The hole perforation plate 60 represents one part of amold and together with a second mold half 82 a mold for a cleaningelement carrier 30 is provided. Then molten material, e.g. polyethyleneis filled into the mold and cleaning element carrier 30 is formed (FIG.3F) wherein the fuse balls 24 are embedded into the material of thecleaning element carrier 30 and thus, mounted securely thereto.

FIGS. 3G-3H show an embodiment, wherein a drive part 44 is furtherintegrated into the cleaning element carrier 30. Therefore, the drive 44is placed partly in the mold so that the molten polyethylene materialsurrounds the fuse balls 24 and a part of the drive part 44. FIG. 3Ishows an embodiment, wherein the hole perforation plate 60 comprises acentral depression 63. Said central depression 63 will form a centralprotrusion 37 in the cleaning element carrier 30 to be formed.

FIG. 4A shows a schematic and cross-sectional view of a manualtoothbrush 14 comprising a handle 13 and a head 12, wherein the head 12comprises a cleaning element carrier 30 as disclosed herein. Thecleaning element carrier 30 comprises several bristle tufts 20, whereinthe bristle tufts 20 are each secured with a fuse ball 24 in thecleaning element carrier 30 and the ends 26 intended for cleaningprotrude therefrom.

FIG. 4B shows a schematic and cross-sectional view of a replacementbrush head 19 for an electric toothbrush comprising a neck 17 and a head16. The head 16 comprises a cleaning element carrier 30 as disclosedherein as well as a drive part 44 and a gear connection 18. The cleaningelement carrier 30 comprises several bristle tufts 20, wherein thebristle tufts 20 are each secured with a fuse ball 24 in the cleaningelement carrier 30 and the ends 26 intended for cleaning protrudetherefrom.

FIG. 5 shows a schematic top view to a front surface 61 of a holeperforation plate 60 comprising three arrangements 65 of holes 70. Thearrangements 65 are separated from each other by a distance of at least2 mm. The holes 70 in the arrangements 65 correspond to and are locatedaccording to the bristle field 28 which shall be formed. Different sizesand shapes of holes 70 are possible, e.g. elongated holes 70 a, ovalholes 70 b, round holes 70 c, arc shaped hole 70 d or trapezoidal holes70 e are shown, but other shapes or sizes might be present depending onthe bristle tufts which shall be used. The hole perforation plate 60further comprises some blind holes 64 which are suitable to receivefurther cleaning elements, such as elastomeric cleaning elements. Moreor less than the three arrangements 65 shown can be present in one holeperforation plate 60. Two or more hole perforation plates 60 can becombined to a larger ensemble.

The dimensions and values disclosed herein are not to be understood asbeing strictly limited to the exact numerical values recited. Instead,unless otherwise specified, each such dimension is intended to mean boththe recited value and a functionally equivalent range surrounding thatvalue. For example, a dimension disclosed as “40 mm” is intended to mean“about 40 mm.”

Every document cited herein, including any cross referenced or relatedpatent or application and any patent application or patent to which thisapplication claims priority or benefit thereof, is hereby incorporatedherein by reference in its entirety unless expressly excluded orotherwise limited. The citation of any document is not an admission thatit is prior art with respect to any invention disclosed or claimedherein or that it alone, or in any combination with any other referenceor references, teaches, suggests or discloses any such invention.Further, to the extent that any meaning or definition of a term in thisdocument conflicts with any meaning or definition of the same term in adocument incorporated by reference, the meaning or definition assignedto that term in this document shall govern.

While particular embodiments of the present invention have beenillustrated and described, it would be obvious to those skilled in theart that various other changes and modifications can be made withoutdeparting from the spirit and scope of the invention. It is thereforeintended to cover in the appended claims all such changes andmodifications that are within the scope of this invention.

What is claimed is:
 1. A method for manufacturing a toothbrush head or apart thereof, the method comprising steps of: providing a plurality ofbristle tufts having a first end intended for cleaning and a second endopposite to the first end; providing a hole perforation plate comprisinga front surface, a back surface, a thickness (D) therebetween, and aplurality of holes grouped into a plurality of hole arrangements,wherein the front surface is uneven in an area of the hole arrangements;pushing the bristle tufts through the holes of the hole perforationplate; and fusing the second ends of the bristle tufts at the backsurface of the hole perforation plate by applying thermal energy,thereby forming a plurality of fuse balls that are larger than the holesof the hole perforation plate; and mounting the hole perforation platewith the plurality of bristle tufts into a brush head.
 2. The method ofclaim 1, wherein the step of providing a hole perforation platecomprises providing the hole perforation plate wherein the plurality ofhole arrangements are identical to one another with respect to at leastone of a number of the holes, a shape of the holes, a size of the holes,and a distance between the holes.
 3. The method of claim 1, wherein thestep of providing a hole perforation plate comprises providing the holeperforation plate wherein the plurality of hole arrangements aredifferent from one another with respect to at least one of a number ofthe holes, a shape of the holes, a size of the holes, and a distancebetween the holes.
 4. The method of claim 1, further comprising a stepof combining the fuse balls with the hole perforation plate by applyingthermal energy or ultrasound welding.
 5. The method of claim 1, furthercomprising a step of over-molding the fuse balls with a plasticmaterial.
 6. The method of claim 5, wherein a position of at least onebristle tuft in the hole perforation plate during the step ofover-molding is different from a position of said at least one bristletuft in the hole perforation plate during the step of fusing.
 7. Themethod of claim 6, wherein the at least one bristle tuft extends fromthe front surface of the hole perforation plate during the step ofover-molding less than said at least one bristle tuft extends therefromduring the step of fusing.
 8. The method of claim 1, wherein the step ofproviding a hole perforation plate comprises providing the holeperforation plate wherein a number of holes in one hole arrangement isselected from the group consisting of a number of from 1 to 60, a numberof from 15 to 40, a number of from 15 to 35, and a number of from 15 to30.
 9. The method of claim 1, wherein the step of providing a holeperforation plate comprises providing the hole perforation plate whereinthe holes are selected from the group consisting of through-holesstructured and configured to receive bristle tufts and blind holesstructured and configured to receive elastomeric cleaning elements. 10.The method of claim 1, wherein the step of providing a hole perforationplate comprises providing the hole perforation plate wherein the holeshave shapes selected from the group consisting of a round shape, an ovalshape, a half-round shape, a sickle shape, an elliptic shape, anelongate shape, and angled shape, a quadrangular shape, a trapezoidalshape, a pentagonal shape, a hexagonal shape, a heptagonal shape, anoctagonal shape, and any combination thereof.
 11. The method of claim 1,wherein the step of providing a hole perforation plate comprisesproviding the hole perforation plate wherein the holes have a sizeselected from the group consisting of a size of from 0.6 mm² to 3 mm², asize of from 1.0 mm² to 2.0 mm², and a size of about 1.5 mm².
 12. Themethod of claim 1, wherein the step of providing a hole perforationplate comprises providing the hole perforation plate wherein a distancebetween adjacent holes in the hole perforation plate is selected from agroup consisting of a distance of from 0.2 mm to 2 mm, a distance offrom 0.4 mm to 1.8 mm, and a distance of from 0.5 mm to 1.2 mm.
 13. Themethod of claim 1, wherein the step of providing a hole perforationplate comprises providing the hole perforation plate made of a materialselected from the group consisting of metal, metal alloys,heat-resistant plastic, ceramic, and any combination thereof.
 14. Themethod of claim 13, wherein the hole perforation plate comprises atleast a first layer made from a first material and a second layer madefrom a second material, the first material being more heat-resistantthan the second material.
 15. The method of claim 14, wherein the firstlayer comprises the front surface of the hole perforation plate and thesecond layer comprises the back surface of the hole perforation plate.16. The method of claim 1, wherein the step of providing a holeperforation plate comprises providing the hole perforation plate whereinthe thickness (D) is selected from the group consisting of a thicknessof from 5 mm to 20 mm, and a thickness of from 6 mm to 14 mm.
 17. Themethod of claim 1, wherein the step of providing a hole perforationplate comprises providing the hole perforation plate wherein the holesof at least one hole arrangement are located at different levels of thehole perforation plate.
 18. The method of claim 1, wherein the step ofproviding a hole perforation plate comprises providing the holeperforation plate wherein the front surface has a convex shape in anarea of at least one hole arrangement.
 19. The method of claim 1,wherein the step of providing a hole perforation plate comprisesproviding the hole perforation plate wherein the front surface comprisesa central depression in an area of at least one hole arrangement, andwherein the central depression includes at least one hole.
 20. Themethod of claim 1, further comprising a step of providing a stopperplate combinable with the back surface of the hole perforation plate,wherein the stopper plate has a surface selected from the groupconsisting of a flat surface and a surface comprising protrusionscorresponding in form and shape to the hole arrangements of the holeperforation plate.
 21. The method of claim 1, wherein the step ofproviding a hole perforation plate comprises providing the holeperforation plate that is a part of a mold.